FIGS. 1A, 1B, 1C and 1D illustrate a standard LED packaging arrangement, such as that employed by the XLamp® 7090 XR-E series of LED products manufactured by Cree, Incorporated, and how that packaged LED lamp may be suitably mounted on a larger printed circuit board (PCB). As seen in FIG. 1A, the packaged LED lamp 100 comprises a lens 102, a reflector 104 and a mounting substrate 106. The arrangement 100 may also be referred to as an LED, LED lamp or a lamp. As seen in FIG. 1B, an LED chip 108 is electrically connected by bond wires 110 and 112 to electrical contact strips 114 and 116, respectively, on the substrate 106 which may suitably be a printed circuit board (PCB), such as a flame resistant 4 (FR4) board. When power is applied through the contacts 114 and 116, chip 108 emits light. The chip 108 is shown as having two top contacts for a chip having a horizontal arrangement. However, alternative LED chips and chip mounting arrangements are possible where the LED has a horizontal or vertical orientation or is flip chip mounted, as would be understood by one of ordinary skill in the art. In the arrangement shown, reflector 104 helps direct the emitted light upwards and the lens 102 focuses the emitted light. The chip 108 is thermally mounted on top surface 118 of substrate 106 with a thermal bonding paste. FIG. 1C shows a bottom surface 120 of the substrate 110 and electrical contacts 114 and 116 along with representative dimensions for the XLamp® 7090 XR-E series of LED products. It will be recognized that 9.0 mm is slightly smaller than 1 cm and is about ⅓ of an inch. As a result, it can be seen that the XLamp® LED products and other similar products have a small form factor compared to typical incandescent bulbs. FIG. 1D shows a solder pad 120 for mounting the packaged LED lamp 100 to a larger PCB.
Reflow surface mount techniques are highly efficient for lamps, such as lamp 100 where bottom contacts 114 and 116 can be reflow soldered to traces of a printed circuit board. However, as LED lamps become more complex with larger numbers of contacts and chips being employed, for example, and a much wider array of different applications, as such lamps are more widely adopted, additional flexibility as to physical mounting and electrical connection arrangements is highly desirable.
For example, two applications assigned to the assignee of the present application address aspects of such needs. See, for example, U.S. application Ser. No. 11,614,261 filed Dec. 21, 2006 and issued as U.S. Pat. No. 7,549,786 and U.S. application Ser. No. 12/335,631 filed Dec. 16, 2009, both of which are incorporated by reference herein in their entirety.